This invention relates broadly to fluid handling apparatus and, more specifically, to fluid handling apparatus of the type which is or can be used with fluids which are or can be harmful to humans and/or to fluids which are corrosive, or are bacterially contaminated, or which are otherwise biohazardous for one reason or another.
The handling of hazardous materials, especially hazardous fluid materials, is a worldwide consummate problem. When a human operator is required to become involved in such handling of these materials, the problem is even more severe. Fluid materials, generally, are particularly troublesome due to their capacity for leaking, corroding, spilling, entering the immediate surroundings in aerosol form, etc.
In the biomedical field and particularly in a hospital environment, the requirement for a safe, sanitary and biologically clean working atmosphere is of the highest order and importance. Additionally, each piece of biomedical apparatus must meet the highest and strictest safety and sanitary codes for biohazard containment. The present worldwide problem of infectious disease, such as the HIV virus, places a high burden on the manufacturer of biomedical apparatus, with respect to the chemistry/reagents involved in using the apparatus, as well as with respect to the human operator, who must interface with and work with such apparatus.
A particular area of concern is that of hematology apparatus and specifically automated hematology apparatus which employs freshly venapunctured human blood as a fluid sample material for diagnosis and detection of disease. Most, if not all, human blood used for test and diagnostic purposes is drawn by needle puncture from veins in the human anatomy. The fresh fluid blood is captured in test tube-like containers or vials which are tightly capped with flexible, puncturable caps or stoppers. Such containers are patient-identified (e.g. bar coded) and then transferred to diagnostic centers for diagnostic examination or to temporary cold storage.
At this juncture in the fluid (blood sample) handling routine, there is relatively little concern vis-a-vis biohazard containment, since the blood, should it be hazardous, is completely sealed from the atmosphere as well as from the person of the handler/operator.
The next step in the routine, however, can create the first of many biohazard problems. If the blood-containing test tube or vial is introduced into the testing apparatus with the tube cap in place, there is little danger to the operator. On the other hand, if the operator is required to remove the cap from the test tube or vial and decant the blood into the test apparatus, there could be substantial risk of contamination to the operator and to the adjacent area.
For example, if the human operator is required to perform a microscopic examination of the blood, then a portion of the fluid blood must be placed on a microscope slide, so as to be viewed under a microscope or other optical instrument for examination. This obviously necessitates some handling of the blood out of the tube or vial. In such case, contamination of the operator can occur at any time from a variety of causes. Not the least of these is tube breakage, slide breakage, blood spillage, etc. A search for automation of these steps has been an ongoing medical industry quest for some time.
Many, if not most, modern medical facilities, hospitals and diagnostic laboratories and centers, universally employ automatic diagnostic hematology tools in an effort to eliminate human error, as well as to reduce the required labor force so as to relieve highly skilled and trained technical personnel for more demanding tasks and, in addition, to prevent the possibility of biohazard contamination. Some of these automated hematology devices are more or less biohazard free due to containment devices, which either prevent easy access to the blood during diagnostic routines or avoid human operator intervention with the blood container until the diagnostic routine is completed. Still, there is the ever-present danger from the technician who tries to "help the machine along", or becomes over-anxious for the results and thereby intervenes in the operation prior to its completion or termination. By removing protective shielding from the blood container, he or she thereby exposes himself or herself to the risk of infection or injury from the hazardous contents, if any.
Certain recently introduced hematology equipment utilizes an automatic so-called "cap piercer, washer aspirator", wherein a capped and bar coded sample vial, containing a sample of human blood, is dropped into a sample carrier, which then automatically reads the bar code, introduces an aspirating needle into and through the vial cap, and withdraws a portion of the blood sample, for use in operably associated diagnostic apparatus. The aspirating needle is withdrawn from the blood sample vial, while simultaneously being washed, and finally retracted out of the way, permitting the next sample to be introduced into the sample carrier of the apparatus.
Such apparatus as the foregoing is reasonably effective in preventing biohazard contamination. However, there comes a time in the operation of the apparatus when, either because of a clog of the aspirating needle, or the fact that the aspirating needle has become bent, dulled or broken, it is necessary to remove this element of the combination and replace it with a new aspirating needle. Obviously, without more, the operator must, in most instances, handle the aspirating needle which, could contain hazardous sample material. Should the operator prick a finger or the skin, the hazardous material could be introduced quickly into the bloodstream of the operator, often with serious or tragic results.